The black soldier fly bioreactor: host-microbiome synergy in pathogen neutralization, xenobiotic remediation, and downstream feed safety.

Black soldier fly larvae (BSFL) are critical to the circular economy, transforming hazardous organic wastes into sustainable agricultural feed. However, processing high-bioburden substrates presents severe biosafety challenges. This review synthesizes recent advancements (2021-2026) regarding the multidimensional role of the BSFL gut bioreactor in waste sanitization and xenobiotic remediation. Pathogen neutralization is driven by a synergistic, tripartite defense system: host-derived antimicrobial peptides (AMPs), biophysical lipid interactions (e.g., lauric acid), and microbiome-mediated competitive exclusion. Concurrently, the gut microbiota deploys novel enzymatic pathways to actively degrade veterinary pharmaceuticals. Despite these sanitization capabilities, a profound biosafety paradox exists: while live, culturable vegetative pathogens and parent chemical antibiotics are eradicated, the intensive selective pressure within the gut environment facilitates horizontal gene transfer, leading to the amplification of antimicrobial resistance genes (ARGs). This study critically evaluates industrial interventions - including chemical pre-treatments, abiotic stress modulation, and probiotic bioaugmentation - designed to engineer the bioreactor and mitigate these genetic and horizontal transfer risks. Finally, the study explores the downstream impacts of BSFL biomass as a functional substitute for antibiotic growth promoters in livestock, highlighting its prebiotic capacity to positively modulate animal microbiomes. Overcoming current methodological and regulatory limitations via multi-omics will cement BSFL as a biosecure pillar of sustainable agriculture. © 2026 Society of Chemical Industry.